JP7344868B2 - Small holeless indexable inserts for cutting tools and cutting tools - Google Patents

Description

The subject matter of the present application relates to machining or cutting tools. In particular, it relates to micro-cutting tools with compact indexable cutting inserts without through-clamp holes.

Generally speaking, replaceable/consumable inserts fixed in a reusable steel body are more cost-effective compared to one-piece cutting tools with sharp cutting edges built into the tool body. It is preferable. At the lower end of the tool size/diameter scale, one-piece tools were dominant. Specifically, this is the case for certain insert sizes, in which case it is impractical to use replaceable inserts, as they cannot be secured to the pocket via a fastener that passes through the insert's clamping hole. becomes (or even becomes impossible). The main reason for this is that for certain sizes, the clamp screw (particularly its head) is too small for a standard screwdriver or wrench. Accordingly, there has been a long-standing need for cutting tools with replaceable cutting inserts for at least a portion of the smaller diameter cutting tool market.

According to a first aspect of the subject matter of the present application, a compact, through-holeless indexable cutting insert is provided. This cutting insert has an inscribed circle that contains exactly three main cutting edges and is in tangential contact with all the main cutting edges only.

According to a second aspect of the subject matter of the present application, there is provided a positioning tool configured to hold and/or maintain a compact indexable imperforate cutting insert, the positioning tool having an elongated shape. Has an outward facing insert retention surface,
The shape of the insert holding surface corresponds to the shape of the side surface of the cutting insert.

According to a third aspect of the subject matter of the present application, there is further provided a tool kit comprising a positioning tool and a compact non-perforated cutting insert.

According to a fourth aspect of the subject matter of the present application, a cutting tool having an insert pocket, a small holeless indexable cutting insert externally fixed in the pocket via a clamping screw, and a positioning tool are provided. Further provided is a tool kit comprising:

According to a fifth aspect of the subject matter of the present application, there is provided a method for replacing a small insert into a positioning tool (typically due to all cutting edges being worn), the method comprising the following steps:
a. attaching the insert retaining surface to any portion of the miniature insert;
b. unclamping or releasing the small insert by loosening the screw;
c. withdrawing the insert from the pocket, removing the insert from the insert retaining surface, and discarding it;
d. attaching the insert retaining surface to the unused flank surface of the replacement cutting insert;
e. inserting the replacement insert into the pocket and tightening the screw.

According to a sixth aspect of the subject matter of the present application, there is further provided a method for indexing small inserts (usually due to worn cutting edges) with a positioning tool, the method comprising the steps of:
a. attaching a retaining surface to an exposed or accessible main flank typically associated with a worn working main cutting edge;
b. unclamping or releasing the small insert by loosening the screw;
c. attaching the tool to the insert;
d. removing the insert from the pocket and indexing the insert so that the unused primary flank is attached to the insert retaining surface;
e. inserting the miniature insert 14 into the pocket 18 and tightening the screw.

Any of the following features, either alone or in combination, may be applicable to any of the above aspects of the subject matter of the present application.

The positioning tool may have a magnetic or magnetized insert retention surface configured to magnetically retain the insert. In some embodiments, the positioning tool may include a natural magnet, and in other embodiments, the positioning tool may include an electromagnet.

The positioning tool may have an electrostatic insert retention surface configured to electrostatically retain the insert.

The positioning tool may have an adhesive insert retention surface to which the insert can temporarily adhere upon contact.

The insert retention surface is elongated in the elongation direction, and the locating tool can further include opposing enlarged gripping surfaces extending in the elongation direction (ED) for gripping when the locating tool is held by an operator. Configured to provide orientation instructions.

The insert retaining surface can have two opposing major edges extending in the direction of elongation and two shorter minor edges extending between the major edges.

The tool body is axially elongated extending away from the positioning head, and the insert retaining surface is the outermost surface projecting axially outwardly from the positioning head.

The miniature insert has three corners, or is triangular in shape, and the insert retaining surface is configured to engage one of the three main flank surfaces of the miniature insert.

The insert retaining surfaces can include opposing, identical major edges ranging from 1.8 to 4.2 mm.

The insert retaining surface connects the opposing major edges and has a minor edge ranging from 1.1 to 2.4 mm.

The positioning tool can be modular, and the rear tool end of the tool body can be configured to be selectively attached to or removed from the drive tool.

The positioning tool can have an elastic sleeve rigidly connected to the positioning head.

The tool body is elongated in an axial direction extending away from the positioning head, the insert retaining surface is elongated in the elongation direction, and in view along the axial direction, the insert retaining surface has a footprint smaller than the footprint of the tool body. Has a footprint.

The positioning head may include two diverging head surfaces extending rearwardly from the insert retaining surface.

The positioning tool can further include a non-ferromagnetic, non-magnetic retaining portion rigidly connected to the tool body and configured to enable gripping and apply torque transmission.

The cutting insert has three main cutting edges and an inscribed circle that tangentially contacts all three main cutting edges.

The inscribed circle can have an inscribed circle diameter ranging from 2.5 mm to 3.8 mm.

The inscribed circle can have an inscribed circle diameter ranging from 2.5 mm to 3.2 mm.

The shape of the insert holding surface corresponds to the shape of the main flank surface of the cutting insert.

The cutting insert is
Opposed top and bottom surfaces of the insert, and an outer circumferential surface of the insert extending between them;
a central axis of symmetry passing through the top and bottom surfaces;
with a maximum insert thickness ranging from 1 mm to 2.5 mm measured along the central axis of symmetry;
including.

The cutting tool can include a fluid channel that opens into at least one insert pocket with a fluid outlet.

The cutting insert can have a main cutting edge with a main cutting edge length in the range of 2 mm to 4 mm.

The cutting insert can include a deflector extending from the main cutting face and configured to deflect the chip.

The cutting insert includes a central axis of symmetry passing through the top and bottom surfaces, about which the cutting insert has rotational symmetry of 120°.

The cutting insert is single-sided, with opposing insert top and bottom surfaces. The bottom surface of the insert is then not configured for machining and has a bottom edge that does not include cutting edges.

The cutting insert is not made of PCD or PCB.

The cutting insert can be pressed to size and no part or surface thereof is ground.

In order to better understand the subject matter of the present application and to show how it can be carried out in practice, reference is made to the attached drawings.

1 is an isometric half-exploded view of a first embodiment of a cutting tool with two small cutting inserts; FIG. FIG. 2 is a side view of the cutting tool of FIG. 1; Figure 2 is a bottom axial view of the cutting tool of Figure 1; Figure 2 is a side view of the miniature insert of Figure 1; FIG. 2 is a top view of the top surface of the small insert of FIG. 1; Figure 3 is an isometric half-exploded view of a second embodiment of a cutting tool with two small cutting inserts; FIG. 7 is a side view of the cutting tool of FIG. 6; Figure 7 is a bottom axial view of the cutting tool of Figure 6; Figure 7 is a side view of the miniature insert of Figure 6; FIG. 7 is a top view of the top surface of the small insert of FIG. 6; 3 is a cross-sectional view of the fluid channel along line XI-XI of FIG. 2; FIG. FIG. 3 is an isometric view of a tool kit including a miniature insert and an embodiment of a modular first positioning tool mounted on a driver. FIG. 3 is an isometric view of an embodiment of a second positioning tool integrated with a driver; FIG. 14 is an axial front view of the second positioning tool embodiment of FIG. 13; 13 is an isolated side view of the first positioning tool embodiment of FIG. 12; FIG. 3 is a third embodiment of the positioning tool without drive means; FIG.

Where deemed appropriate, reference numbers may be repeated between the drawings to indicate corresponding or similar elements.

The following description describes various aspects of the subject matter of the present application. For purposes of explanation, specific structures and details are described in sufficient detail to provide a thorough understanding of the subject matter of the present application. However, it will be apparent to those skilled in the art that the subject matter of the present application may be practiced without the specific arrangements and details presented herein.

Attention is directed to FIGS. 1 and 7. The machining or cutting tool 12 includes one or more small, non-porous indexable cutting inserts 14 secured within a pocket 18 of the cutting tool 12 .

The miniature insert 14 is indexable, perforated, positive, three angled, or triangular. The cutting tool 12 has a longitudinal rotation axis A.

The term "undersized" refers to cutting inserts that are smaller than currently available interchangeable "one-piece" (i.e., not brazed or made from two or more main parts) cutting inserts14. used to explain. In other words, these miniature inserts 14 are so small that they can be wrapped up or even hidden between two fingertips.

For this purpose, an insert is said to be "compact" if it meets one or more predetermined size and geometric criteria, as described further below.

The cutting tool 12 may optionally include a positioning tool 16 (FIGS. 12-15). Indexing, installation or replacement of these small inserts 14 can be done manually and optionally with a positioning tool 16. These tasks may also be performed using the positioning tool 16 in combination with two fingers, as described further below.

The positioning tool 16 is configured such that the cutting edge is visible even when the small insert 14 is held (as opposed to holding the insert 14 by hand, where the cutting edge is perhaps not visible). Additionally, the positioning tool 16 is configured to hold the insert 14 in a particular orientation, to accurately secure and position the insert 14 within the pocket 18, and to accurately identify worn cutting edges. Ru. For example, if the cutting edge becomes worn, the operator may maintain the insert 14 with the locating tool 16 via the flank surface associated with the worn cutting edge of the insert 14, remove the insert 14 from the pocket 18, and remove the insert 14 from the locating tool 16. 14 and return the insert 14 to the pocket 18 in the desired orientation (ie, with the unused cutting edge facing outward).

Thus, according to one embodiment of the subject matter of the present application, the positioning tool 16 is provided as part of a tool kit 10 that includes the positioning tool 16, the cutting tool 12, and one or more miniature inserts 14. . According to another embodiment, tool kit 10 includes only positioning tool 16 and small insert 14.

Attention is paid to FIGS. 12 to 15. The positioning tool 16 has opposing forward tool ends 20 and rear tool ends 22. At the forward tool end 20, the positioning tool 16 has a positioning head 24 having an integral one-piece construction. At rear tool end 22 , positioning tool 16 includes a tool body 26 rigidly and permanently attached to positioning head 24 .
The tool body 26 may be made of plastic or a suitable non-magnetized non-ferromagnetic material.

The positioning head 24 has an elongated, preferably cylindrical shape. Positioning head 24 is located at forward tool end 20 and has an axially outwardly facing insert retaining surface 28 .

For purposes of this invention, an "insert retention surface" is one that maintains the miniature insert by applying an attractive force to the surface of the insert 14. Insert retention surface 28 relies on attractive forces, such as magnetic or electrostatic forces, to retain insert 14. Alternatively, the insert retaining surface may be an adhesive surface that temporarily adheres to the insert 14 upon contact.

Insert retaining surface 28 projects axially outward from positioning head 24 . In other words, the insert retaining surface 28 is the outermost portion of the positioning head 24 in its axial direction. This is advantageous for better holding the insert 14 without interference and better defining its orientation for viewing. Insert retention surface 28 is configured to engage and retain miniature insert 14 . Accordingly, the insert retaining surface 28 has an asymmetric shape configured to match or correspond to the shape of the side or circumferential side of the miniature insert 14 (generally, most inserts have elongated or circumferential sides). Specifically, the insert has an elongated shape, at least in plan view of the flank face of the insert (which is in contrast to the view of the rake face of the insert, where symmetrical shapes are much more common).

In a preferred embodiment, the attractive force is a magnetic force, as explained further below. The positioning tool 16 is therefore a magnetic positioning tool 16 having a positioning head 24 provided with a magnetic insert retaining surface 28 . In such embodiments, head 24 and insert retaining surface 28 generate either a magnetic field formed from naturally magnetic material or a magnetic field formed from ferromagnetic material. Additionally, in some embodiments, magnetic positioning tool 16 may include an electromagnet.

Pay attention to FIG. In plan view, the magnetic insert retaining surface 28 has a peripheral edge with a closed elongated shape, which defines an elongation direction ED. In other words, in the first direction (elongation direction ED), the shape of the magnetic insert retaining surface 28 has a maximum dimension that is larger than its maximum dimension in the second direction perpendicular to the elongation direction ED. The shape of the magnetic insert retaining surface 28 corresponds to or matches the sides of the miniature insert 14. Specifically, the miniature insert 14 is aligned with the elongation direction ED (as seen in FIG. 14) by attractive forces in the installed position (when the magnetic insert retaining surface 28 is in contact with the side of the miniature insert). and respond accordingly. The term "corresponding" refers to the similarity in geometric shape between the shape of the magnetic insert retaining surface 28 and the shape of the sides of the miniature insert 14 (e.g., if one shape is rectangular, the corresponding It is used to indicate that the shape is not round. This means that when the magnetic insert retaining surface 28 is brought sufficiently close to any side or side circumferential surface or flank surface 82 of the miniature insert 14, the magnetic Advantageously, the tensile force can reorient the insert 14 to match or correspond to the orientation of the magnetic insert retaining surface 28.

Additionally, the magnetic positioning tool 16 includes a retaining portion 30 that includes opposing gripping surfaces 32 that provide an operator grip and allow the magnetic positioning tool 16 to be easily torqued. Retaining portion 30 is located rearwardly spaced from magnetic insert retaining surface 28 . Opposing gripping surfaces 32 extend in the elongation direction ED. The gripping surface 32 may be parallel to the elongation direction ED. This feature is advantageous because it allows the operator to easily establish or easily estimate the orientation of the magnetic insert retaining surface 28 and, subsequently, the miniature insert 14.

The magnetic insert retaining surface 28 has the same area or a smaller area when compared to the axial cross section of the positioning head 24. In other words, the magnetic insert retaining surface 28 has the smallest footprint of the magnetic positioning tool 16 in an axial view of the magnetic positioning tool 16 or in a top view of the magnetic insert retaining surface 28 .

Attention is again drawn to FIG. 14. For example, the magnetic insert retaining surface 28 may have a generally rectangular shape having a pair of opposing major edges 36 extending in the elongation direction ED and a pair of opposing minor edges 38 (which may not be straight). I can do it. Positioning head 24 may include head surfaces 34, each head surface 34 extending from a respective major edge 36. Head surface 34 diverges away from magnetic insert retaining surface 28 . The head surface 34 may be flat and configured to assist the operator in establishing the correct orientation and indexing position of the electrically magnetically retained mini-insert 14 (particularly when the operator 14).

According to the subject matter of the present application, magnetic positioning tool 16 can have three magnetic positioning tool embodiments.

Attention is paid to FIGS. 12 and 15. According to the first magnetic positioning tool embodiment, the magnetic positioning tool 116 is modular and can be securely attached/reattached to most drivers 42 or tools. Specifically, the rear tool end 22 is configured to be mounted or clamped onto/into the driver rear end 44 (non-drive end). For example, rear tool end 22 may include a non-magnetic, non-ferromagnetic coupling portion or sleeve 40 that couples magnetic tool 116 to another tool, such as, for example, driver 42. configured to be or to be attached.

Attention is paid to FIGS. 13 and 14. According to a second magnetic positioning tool embodiment, the magnetic positioning tool 216 has a positioning head 24 that is an integral part of the driver 42, specifically the driver rear end 44 (i.e., the non-drive end thereof). . The magnetic tool 216 can be, for example, glued and pressed into a dedicated recess or screwed into or onto the driver rear end 44.

Pay attention to FIG. According to a third magnetic positioning tool embodiment, the magnetic positioning tool 316 is a separate tool that assists the operator in positioning, holding, and indexing the insert 14 as disclosed above. Configured for assistance only. According to this embodiment, the magnetic tool 316 does not include a drive means such as a Torx interface/key. The magnetic positioning tool 316 includes a retaining portion 330 at the rear tool end 322.

The miniature insert 14 is typically made from an extremely hard, wear-resistant material such as cemented carbide by pressing and sintering carbide powder in a binder. Further, the cemented carbide may be, for example, tungsten carbide. Cutting insert 14 may be coated or uncoated. The miniature insert 14 is preferably not made of PCD (polycrystalline diamond) or PCB (polycrystalline boron). Preferably, the miniature insert 14 is not demagnetized. However, during testing, the magnetic positioning tool 16 functioned well and properly held even demagnetized inserts.

Insert 14 is preferably pressed to size. In other words, no part or surface of the insert 14 is ground. This is a substantial advantage both in terms of production efficiency and cost effectiveness. Furthermore, in addition to the inherently costly grinding process, additional costs are incurred when grinding these small "nano" inserts compared to larger inserts. Due to issues with insert size, machines capable of holding these inserts that need to be ground, even if developed, are found to be fairly expensive and prone to reliability problems. It was done.

The miniature insert 14 has opposing insert top and bottom surfaces 48 and 50 and an insert outer circumferential surface 52 extending therebetween. The insert 14 has a rotational symmetry of 120° with respect to a central axis of symmetry CA passing through the insert top and bottom surfaces 48,50. The insert 14 is therefore indexable in three directions about its central axis of symmetry CA. The insert 14 has a virtual intermediate surface MP, which is perpendicular to the central axis CA, located between the insert top surface 48 and the bottom surface 50, and intersects with the insert outer circumferential surface 52. The maximum thickness MIT of the insert is measured between the outer edges of the top surface 48 and bottom surface 50 of the insert in a direction parallel to the central axis CA. The maximum insert thickness MIT preferably ranges from 1.0 to 2.5 mm.

Insert top surface 48 has a circumferential top edge 54 . Top edge 54 includes exactly three actuating portions 56 configured to act on the workpiece. As further disclosed below, each actuating portion 56 may include, for example, a main cutting edge 58, a corner cutting edge 60, and/or an angled cutting edge 62. Each working portion 56 may also include a wiper edge 64 configured not to remove material, but rather to smooth or improve the surface quality of the workpiece. Insert top surface 48 may include at least one abutment projection 55 that projects beyond top edge 54 in side views of insert 14 (FIGS. 4 and 9). The protrusion extends further outward than any other portion of the insert top surface 48 with respect to the intermediate plane MP. Each abutment projection 55 includes a deflection surface or deflector 57 .

Each main cutting edge 58 can have a main cutting edge length CEL in the range of 2 to 4 mm.

Insert top surface 48 includes a top abutment surface 68 configured to abuttingly engage screw 74 to secure insert 14 within pocket 18 . Each top abutment surface 68 includes exactly three top abutment subsurfaces 76 configured to engage screws 74 . The top abutment surface 68 can have a triangular shape in its top view (FIGS. 5 and 10). The top abutment surface 68 may be attached to the top surface of the insert depending on the orientation of the thread 74 relative to the orientation of the insert 14 and, in turn, depending on the orientation of the insert 14 relative to the cutting tool 12 (as seen in FIG. 10, for example). 48 about the central axis CA.

Insert top surface 48 includes a main rake surface 70 . Each major rake face 70 may be disposed between the top edge 54 and the abutment projection 55. Each main rake face 70 can extend from a respective main cutting edge 58 and merge with a respective deflector 57 on the abutment projection 55 . In other words, each deflector 57 is located farther from the center axis CA than its respective rake face 70 and closer to the intermediate plane MP than the top contact surface 68.

Attention is directed to FIGS. 5 and 10. According to this embodiment, insert 14 can have a non-equilateral triangular shape or can have an equilateral triangular shape, for example, in a top or plan view of insert top surface 48 . The inscribed circle IC is defined between (or tangent to) three identical main cutting edges 58 of the top edge 54 . The inscribed circle IC has an inscribed circle diameter ICD in the range 2.5-3.8 mm, preferably in the range 2.5-3.2 mm.

Although the range of inscribed circle diameter ICD mentioned above leaves no room for a suitable functional clamping hole (i.e. capable of accommodating a suitable/usable screw with a usable screw head size) , yet maintain proper insert structure. In other words, an insert that is too small may become too weak to be used, and/or the clamping hole only accommodates a screw that is too small to be suitable for securing the cutting insert within the pocket. It turns out. Therefore, these inserts 14 do not have clamp holes or any other openings and are therefore considered "holeless." Not having clamp holes is advantageous, at least because the inserts are more robust, and the manufacturing process is cheaper compared to inserts with holes (by pressing the powder, the through-clamp holes can be made (no extra punch needed to create one).

Insert bottom surface 50 includes a bottom abutment surface 78 . Bottom abutment surface 78 is preferably flat. Insert bottom surface 50 has a bottom edge 80 that can lie in a single plane. Bottom edge 80 is not configured for machining or cutting of any kind. The insert 14 is therefore single-sided or single-sided. The insert bottom surface 50 may include a recess centrally located in the bottom abutment surface 78, thereby providing for engagement between the bottom abutment surface 78 and the respective abutment surface within the pocket 18 (as described in the art). It is possible to improve the three-point engagement known as

The insert outer circumferential surface 52 extends from the top edge 54 and converges toward the bottom edge 80 (as it approaches the central axis CA). Additionally, no portion of the bottom edge 80 is visible in the top view of the insert top surface 48 (FIGS. 5 and 10). Insert 14 is thus defined as a positive insert 14 or as is known in the art as an insert having a positive cutting profile. These miniature inserts have positive cutting geometries that are easier to manufacture and press, especially since these inserts have pressed-to-size geometries and cutting edges.

Thus, the miniature insert 14 may have a top and/or bottom surface with recesses, indentations, and other features, but lacks through holes through which the clamping element can pass and secure the insert in the pocket. Note that it is still considered "non-perforated" as long as the

Pay attention to FIGS. 1 to 5. According to a first insert embodiment, the miniature insert 14 is a high feed cutting insert 114 as known in the art. Each working portion 156 includes an angled cutting edge 162 that is laterally connected to a main cutting edge 158 that is connected to a corner cutting edge 160 (in plan view of the insert top surface 148, as seen in FIG. 5). . The actuating portion 156 can include a minor corner cutting edge 166 connecting the angled cutting edge 162 and the main cutting edge 158. Each inclined cutting edge 162 is formed at the intersection between an inclined rake face 184 and an inclined flank face 186. Each main cutting edge 158 is formed at the intersection of the main rake face 170 and the main flank face 172. The major flank surface 172 is preferably flat and configured to abut the insert retaining surface 28 of the magnetic positioning tool 16 and the respective wall of the pocket, as described below. Each corner cutting edge 160 is formed at the intersection of a corner rake face 188 and a corner flank face 190. Each of the rake faces is formed on the insert top surface 148. Each of the relief surfaces is formed on the insert outer circumferential surface 152.

According to the first insert embodiment, the main cutting edge length CEL is equal to 2.5 mm and the inscribed circle diameter ICD is equal to 3.0 mm.

Attention is paid to FIGS. 6 to 10. According to a second insert embodiment, the miniature insert 14 is a shouldering insert 214, as is known in the art. The shouldering insert is configured to mill right angle shoulders in the workpiece within a tolerance of 1-2°. Each working portion 256 includes a main cutting edge 258, a wiper blade 264, and a corner cutting edge 260 extending therebetween. Each actuation portion 256 may also include an angled cutting edge 262 extending between a wiper blade 264 and a main cutting edge 258 of an adjacent actuation portion 256 . In other words, the inclined cutting edge 262 of the first working part 256 is part of the main cutting edge 258 of the adjacent second working part 256, has the same orientation, and is continuous. Therefore, if the application requires a deeper shoulder, the "extended main cutting edge" 258 can be achieved simply by defining a deeper cutting depth. In such a case, the operator may decide to use the entire combined length of the inclined cutting edge 262 of the first working part 256 and the main cutting edge 258 of the second working part 256 to reduce the length of said extended A main cutting edge 258 can be achieved. Each main cutting edge 258 is formed at the intersection of the main rake face 270 and the main flank face 272. Each inclined cutting edge 262 is formed at the intersection between an inclined rake face 284 and an inclined flank face 286. Each corner cutting edge 260 is formed at the intersection of a corner rake face 288 and a corner relief face 290. Each of the rake faces is formed on the insert top surface 248. Each of the relief surfaces is formed on the insert outer circumferential surface 252. Peripheral surface 252 further includes wiper relief surfaces 265, each extending from a respective wiper blade 264. Peripheral surface 252 further includes side abutment surfaces 253 extending between each major flank surface 272 toward bottom edge 80 .

According to the second insert embodiment, the main cutting edge length CEL is equal to 2.8 mm and the inscribed circle diameter ICD is equal to 2.8 mm.

Attention is directed to FIGS. 1 and 6. Cutting tool 12 has a cutting body 91 and a cutting portion 92 extending therefrom and including at least two pockets 18 . The one or more pockets 18 are what are known in the art as radially oriented pockets or radial pockets 18. The insert 14 is therefore also referred to as a radial insert.

Each pocket 18 can have a pocket base surface 93 and two pocket walls 94 extending therefrom. Pocket walls 94 can also be perpendicular to pocket base surface 93. According to the first insert embodiment, the two pocket walls 194 converge inwardly in a direction substantially parallel to the axis of rotation A (as seen in FIG. 1). According to the embodiment of the second insert 214, the two pocket walls 294 converge inwardly in a direction perpendicular to the axis of rotation A (as seen in FIG. 6).

Each pocket 18 includes a wedge-shaped arrangement that secures these small, imperforate inserts 14. The insert 14 can be attached to any other part of the cutting tool 12 or any type of adapter/cartridge to ensure simple, quick and cost-effective replacement or indexing of the insert 14 itself (without adapters or shims). The parts are not glued or brazed in any way. Each pocket 18 includes a screw 74 that is screwed into a threaded hole 95 in the cutting tool 12 without passing the insert 14 through. Threaded holes 95 are not located in pocket base surface 93. Screw 74 is configured to directly contact insert 14 and force insert 14 against pocket base surface 93 (ie, insert 14 is wedged therebetween). Screw 74 also pulls insert 14 toward and against pocket wall 94 locating insert 14 within pocket 18 . According to the first insert embodiment, at least one main flank 172 abuts the respective pocket wall 194. According to the second insert embodiment, at least one lateral abutment surface 253 abuts the respective pocket wall 294. When screw 74 is tightened, screw 74 engages top abutment surface 68 and, specifically, screw 74 abuts one of top abutment subsurfaces 76 .

Each pocket 18 may further include an internal fluid channel 96 extending along cutting body 91 and opening into pocket 18 at a fluid outlet 98 . A fluid outlet may be located adjacent to threaded hole 95. Fluid channel 96 and fluid outlet 98 are separated from threaded hole 95. A fluid channel 96 can be positioned between the two pocket walls 94.

Torque drivers are well known and are sometimes supplied/recommended for use with tools in the art (ie, mini cutting tools containing small screws). This is because such small diameter fasteners can be damaged or broken rather easily. These torque drivers include a torque limiting mechanism that is calibrated to prevent the operator from exceeding recommended torque limits when applying torque to the respective screw size.

Standard/regular driver 42, ie, a torque driver, includes opposed driver front and rear ends 43 and 44, and a driver body 46 extending therebetween. The driver 42 has a driver rotation axis DRA. The driver front end 43 includes a key or torque transmitting feature, such as a TORX®. Driver body 46 includes a driver retention portion 30 configured to provide gripping. The driver retaining portion 30 may extend radially outwardly in a direction away from the driver rotation axis DRA on either one or both of its two opposing sides.

The method of replacing a small insert 14, 114, 214 with a magnetic positioning tool 16, 116, 216, 316 (usually due to all cutting edges being worn) involves the following steps:
a. attaching the insert retaining surface 28 to any portion of the miniature insert 14, 114, 214;
b. unclamping or releasing the miniature insert 14, 114, 214 by loosening the screw 74;
c. withdrawing the insert 14, 114, 214 from the pocket 18, removing the insert 14, 114, 214 from the insert retaining surface 28, and discarding it;
d. attaching the insert retaining surface 28 to the unused main flank 172 or side abutment surface 253 of the replacement cutting insert 14, 114, 214;
e. inserting the replacement insert 14, 114, 214 into the pocket 18 and tightening the screw 74;
can include.

A method for indexing small inserts 14, 114, 214 (usually due to worn cutting edges) using a magnetic positioning tool 16, 116, 216, 316 includes the following steps:
a. attaching the magnetic retention surface 28 to the exposed or accessible main flank 172 or side abutment surface 253 associated with the normally worn working main cutting edge 58, 158, 258;
b. unclamping or releasing the miniature insert 14, 114, 214 by loosening the screw 74;
c. attaching a magnetic tool 16, 116, 216, 316 to the insert 14, 114, 214;
d. removing the insert 14, 114, 214 from the pocket 18 and indexing the insert such that the unused main flank 172, 272 is attached to the insert retaining surface 28;
e. inserting the small insert 14 into the pocket 18 and tightening the screw 74;
can include.

Claims (13)

A small indexable cutting insert (14, 114, 214) without a through hole,
The cutting insert (14) includes opposing insert top and bottom surfaces (48, 148, 248, 50),
said insert top surface has a circumferential top edge (54) containing exactly three actuating portions (56) in sequence;
Each working part (56) has exactly one of the three main cutting edges (58, 158, 258);
The cutting insert (14, 114, 214) has an inscribed circle (IC) that is in tangential contact only with all main cutting edges (58, 158, 258);
the inscribed circle (IC) has an inscribed circle diameter (ICD) of less than 3.8 mm;
The cutting insert (14, 114, 214) has at least one abutment protrusion (55) projecting beyond the top edge (54) in a side view of the cutting insert (14, 114, 214). ,
The abutment protrusion (55) has a deflector (57) extending from the main rake face (170, 270) and configured to deflect the chip;
The cutting insert (14, 114, 214) is made of cemented carbide rather than PCD or PCB;
The insert top surface (48, 148, 248) has a top abutment surface (68) that includes exactly three top abutment sub-surfaces (76);
A cutting insert in which each of the three adjacent top abutment sub-surfaces (76) has a step discontinuity . The cutting insert (14, 114, 214) of claim 1, wherein the inscribed circle (IC) has an inscribed circle diameter (ICD) in the range of 2.5 to 3.8 mm. The cutting insert (14, 114, 214) is
an insert outer peripheral surface (52) extending between the opposing insert top and bottom surfaces (48, 148, 248, 50);
a central axis of symmetry (CA) passing through the insert top and bottom surfaces (48, 148, 248, 50);
a maximum insert thickness (MIT) ranging from 1 to 2.5 mm measured parallel to the central axis of symmetry (CA);
A cutting insert (14, 114, 214) according to claim 1 or 2, comprising: In a plan view of the insert top surface (48, 148, 248), the main cutting edge (58, 158, 258) has a main cutting edge length (CEL) in the range of 2 to 4 mm. 3. The cutting insert (14, 114, 214) according to any one of 3. The cutting insert (14, 114, 214) is
an insert outer peripheral surface (52) extending between the opposing insert top and bottom surfaces (48, 148, 248, 50);
a central axis of symmetry (CA) passing through the top surface and the bottom surface (48, 148, 248, 50),
Cutting insert (14, 114, 214) according to any one of claims 1 to 4, wherein the cutting insert (14) has a rotational symmetry of 120° about the central axis of symmetry (CA). The opposing insert top and bottom surfaces (48, 148, 248, 50) include top and bottom edges (54, 80);
A cutting insert (14, 114, 214) according to any of the preceding claims, wherein no part of the bottom edge (80) is visible in a plan view of the insert top surface (48). Cutting insert (14, 114, 214) according to any one of claims 1 to 6, wherein the inscribed circle (IC) has an inscribed circle diameter (ICD) in the range 2.5 mm to 3.2 mm. ). the cutting insert (14, 114, 214) is single-sided and positive;
Cutting insert (14, 114) according to any one of claims 1 to 7 , wherein the insert bottom surface (50) is not configured for machining and comprises a bottom edge (80) without cutting edges. , 214). Cutting insert (14, 114, 214) according to any one of claims 1 to 8 , wherein the cemented carbide is tungsten carbide. Cutting insert ( 14 ; 114, 214). The cutting insert (14, 114, 214) according to any one of claims 1 to 10 ,
an insert pocket (18) configured and dimensioned to secure said cutting insert (14, 114, 214);
A cutting tool (12) comprising: The cutting tool (12) according to claim 11 , wherein the cutting tool (12) comprises a fluid channel (96) opening into the at least one insert pocket (18) with a fluid outlet (98). A small holeless indexable cutting insert (14, 114, 214) externally fixed in the insert pocket (18) of the cutting tool (10) according to claim 11 or 12 by means of a clamping screw (74). A method of indexing or exchanging, the method comprising:
a. providing a positioning tool (16, 116, 216, 316);
b. Contacting the exposed or accessible main flank (172) or side abutment surface (253) associated with the normally worn working main cutting edge (58, 158, 258) with the insert retaining surface (28) and thereby maintaining said cutting insert (14, 114, 214);
c. loosening the clamp screw (74) to release the cutting insert (14, 114, 214) from the insert pocket (18);
d. removing said cutting insert (14, 114, 214) from said pocket (18) with said positioning tool (16, 116, 216, 316) and manually indexing or replacing said cutting insert (14, 114, 214); the main flank surface (72, 172, 272) of the unused cutting edge is attached to and retained thereby by the insert retaining surface (28);
e. inserting the indexed or replaced cutting insert (14, 114, 214) with the positioning tool (16, 116, 216, 316) into the pocket (18);
f. tightening the clamp screw (74) to secure the cutting insert (14, 114, 214) in the insert pocket (18);
including methods.

Images